1. Field of the Invention
The present invention relates to a stable gelled composition, in particular a topical composition, which contains a large amount of electrolyte or a primary alcohol and to its use, treatment, protection and/or care of the skin, scalp, mucous membranes, nails and/or hair.
2. Discussion of the Background
Gelling agents are frequently used for topical application in the cosmetic, dermatological and pharmaceutical fields in the form of gels or emulsions for improving the consistency of the composition. The majority of gelling agents conventionally used are aqueous gelling agents and in particular carboxyvinyl polymers, which are neutralized with a base. However, some compounds cannot be used in these compositions because they are incompatible with gelling agents. For example, electrolytes, e.g., inorganic and organic salt, are incompatible with carboxyvinyl polymer gelling agents because they "break down" and liquify emulsions gelled with carboxyvinyl polymers. Thus, compositions containing carboxyvinyl polymers and electrolytes are often devoid of a good consistency.
Electrolytes are particularly desirable components of thickened, topical gel compositions where they have a beneficial effect on the skin or hair and are used in combination with cosmetic, dermatological, and/or pharmaceutical active agents.
Polysaccharide-type gelling agents, such as guar gums, xanthan gums and cellulose derivatives, have been used in place of carboxyvinyl polymers. EP-A-654270 describes a topical composition intended for the treatment of acne and seborrhoeic dermatitis containing a mixture of salts and hydroxyethyl cellulose as the gelling agent. However, these compositions, especially aqueous gels containing no oily phase, have an unsightly lumpy appearance. In addition, they leave the skin "wet looking" after application because these compositions do not penetrate sufficiently into the skin. Therefore, these materials have limited use as cosmetic and/or dermatological agents, where product appearance is critical. The combination of these cellulose derivatives with another thickening agent, such as silicate as described in WO-A-93/8230, provides compositions with the same disadvantages.
Furthermore, the incorporation of primary alcohol and in particular of ethanol into gelled compositions result in the same problems of stability. It is important to be able to use gelled compositions comprising a primary alcohol because the primary alcohol is often needed as solvent for solubilization of active agents.
Therefore, the need remains for gel compositions which overcome the disadvantages of known gelling agents: lack of consistency, instability, lumpy appearance, unpleasant sensation to the touch and incompatibility with electrolytes.
The present inventor has now unexpectedly found a class of associative polymers, in combination with an oxyalkylenated polymer, that stabilize compositions containing a high content of electrolyte and/or of primary alcohol.